Stabilization of metallic phases through formation of metallic/semiconducting lateral heterostructures

In this study, we develop a new approach for stabilization of metallic phases of monolayer MoS₂ through the formation of lateral heterostructures composed of semiconducting/metallic MoS₂. The structure of metallic (a mixture of T and T') and semiconducting (2H) phases was unambiguously characterized by Raman spectroscopy, x-ray photoelectron spectroscopy, photoluminescence imaging, and transmission electron microscope observations. The amount of NaCl, reaction temperature, reaction time, and locations of substrates are essential for controlling the percentage of metallic/semiconducting phases in lateral heterostructures; loading a large amount of NaCl at low temperatures with short reaction times prefers metallic phases. The existence of the semiconducting phase in MoS₂ lateral heterostructures significantly enhances the stability of the metallic phases through passivation of reactive edges. The same approach can be applied to other transition metal dichalcogenides (TMDs), such as WS₂, leading to boosting of basic research and application of TMDs in metallic phases.